The dielectric relaxation has been investigated for a segmented copolyester film containing 76% hard segments (PBT) and 24% soft tetramethylene oxide segments grown under different conditions. Distinct features have been noted in the α- and β-relaxations peaks of dielectric loss spectra depending on whether the samples were melt-grown or solution-cast. These differences have been attributed to the changes in morphology and chain configuration, especially the (CH2)4O groups, caused by the preparative technique used. © 1991.